i have re installed from scratch and there is no change unfortunatly

Just a stupid question, but did you activate the developer mode?

no to test the use of the massmailng apps i'm not in dev mode. :)

Try it...

with or without devmode activated it don't works. on log i can see:

"GET /mass_mailing/field/email_template?&model=mail.mass_mailing&field=body_html&res_id=&callback=FieldTextHtml_22&enable_editor=1&translatable=1&lang=en_US&datarecord={"id":false,"state":"draft","scheduled":0,"failed":0,"next_departure":false,"sent":0,"received_ratio":false,"opened_ratio":false,"replied_ratio":false,"clicks_ratio":false,"bounced_ratio":false,"active":true,"email_from":"Administrator <my_email@my_domain.com >","name":false,"mailing_model":"mail.mass_mailing.contact","attachment_ids":[],"keep_archives":false,"reply_to_mode":"email","reply_to":"Administrator <my_email@my_domain.com >","schedule_date":false,"create_date":false,"sent_date":false,"mass_mailing_campaign_id":false,"contact_ab_pc":100} HTTP/1.0" 200 -

OK i found the solution. it was the add_header X-Frame-Options options in Nginx with the wrong parametter.

in my /etc/nginx/snippets/ssl-params.conf file i had

add_header X-Frame-Options DENY;

i replace the parameter by

add_header X-Frame-Options SAMEORIGIN;

and it works :)